Trichodesma zeylanicum (Burm.f.) R.Br.

Global description
 
Trichodesma zeylanicum is an upright plant, branched, reaching up to 1.5 m high, covered with stiff hairs, quite dense, giving the plant a grayish tint. It is often lignified at the base. On the young stems, red dots are visible. The leaves are simple and alternate, narrowly oval or oblong. The flowers are arranged in loose and branched terminal inflorescence. They are funnel-shaped, pale blue in color with white center. The fruit is a dry capsule splitting into four loculus, each containing a seed.
 
Cotyledons
 
Oval to oblong cotyledons. The petiole is short, flat with a slight bulge on the underside. It has a width of about 2 mm. It is covered with small white hairs. The glabrous lamina measures 10 to 18 mm long and 8 to 16 mm wide. The top is broadly rounded whereas the base is wedged.
 
First leaves
 
First leaves simple, opposite and covered with a light pubescence. They are sessile, elliptical and measure 1.5 to 3.5 cm long. The whitish venations are already protruding on the underside.
 
General habit
 
Plant with upright growth habit. This plant measures 30 to 150 cm high and can be much branched. Its steep and dense pubescence makes its feel raspy and gives it a grayish tint.
 
Underground system
 
The root is a deep taproot, often lignified.
 
Stem
 
Stem is cylindrical, solid, covered with stiff hairs. When young, it is light green in colour, tinged with rose, and with red dots. It quickly becomes woody at the base.
 
Leaf
 
Simple, opposite leaves at the base of the plant, becoming alternate at the top. They are sessile (but not amplexicaule) or carried by a short petiole whose length is less than 10 mm. The leaf blade is narrowly oval to oblong or elliptical. The apex can be obtuse or acute, the base is attenuated or cordate. The margin is entire. Leaf size varies greatly, depending on whether the leaves are inserted on the main stem or neighboring leaves of the inflorescences. In the first case, they are large in size with a length of 6 to 15 cm and a width of 1 to 5 cm. At the top of the plant or at the inflorescences, size decreases. The leaves measure 2 to 5 cm long. Both sides are covered with white stiff hairs, 0.5 to 0.8 mm long, tuberculate at the base. The pinnate venation is prominent on the underside.
 
Inflorescence
 
Inflorescences in loose cymes, located at the ends of branches.
 
Flower
 
The flowers are solitary, long stalked in the leaf axils. The calyx consists of 5 sepals narrowly oval, 7 to 10 mm long, highly keeled and strongly pubescent. The corolla, funnel shaped, is 8 to 10 mm long. It consists of 5 long rounded lobes, 3 to 4 mm. It is usually pale blue but also has white traces and the center is sometimes tinged with pink. The stamens are joined forming a tube.
 
Fruit
 
The fruit is a capsule with 4 ovoid indehiscent loculus, about 4 mm long. They are straightened against each other, forming a cone, underpinned by persistent sepals, spread out in a star. The smooth integument on the outer side becomes rough on the inner side. It is leathery, brown in color tinged with black or sometimes beige. The style is persistent even when the capsules have fallen. Each cell contains a single seed.
 
Seed
 
Seed semi-ellipsoidal, 3 mm long and 1.5 mm wide. The ventral surface is smooth while the dorsal side is curved and coarsely corrugated.

https://www.gbif.org/fr/species/7294697